Wadih Y. Matar

Treatment of failed arthroscopic acetabular labral debridement by femoral chondro-osteoplasty: A CASE SERIES OF FIVE PATIENTS

Femoroacetabular impingement is recognised as being a cause of labral tears and chondral damage. We report a series of five patients who presented with persistent pain in the hip after arthroscopy for isolated labral debridement. All five had a bony abnormality consistent with cam-type femoroacetabular impingement. They had a further operation to correct the abnormality by chondro-osteoplasty of the femoral head-neck junction. At a mean follow-up of 16.3 months (12 to 24) all had symptomatic improvement.

Open Wedge High Tibial Osteotomy A Roentgenographic Comparison of a Horizontal and an Oblique Osteotomy on Patellar Height and Sagittal Tibial Slope

Background In patients with unicompartmental medial knee arthritis, medial opening wedge high tibial osteotomy is used to shift the mechanical weightbearing line laterally to reduce pain and improve function. There have been concerns that opening wedge high tibial osteotomy is associated with a reduction of patellar height and increase in the sagittal posterior tibial slope, both of which can adversely affect the final result. Hypothesis A more distal oblique osteotomy at the level of insertion of the patellar tendon should decrease these effects when compared with a horizontal osteotomy made proximal to the patellar tendon insertion. Study Design Cohort study; Level of evidence, 3. Methods Review of 22 horizontal and 19 oblique high tibial osteotomies with a mean follow-up of 4.2 ± 1.8 years (mean ± SD) was performed. Anatomic tibiofemoral angle, mechanical weightbearing line, medial coronal tibial plateau angle, patellar height (Blackburne and Peel ratio), and sagittal tibial slope were measured. Results In both groups, the weightbearing line was equally shifted toward the center of the plateau. In the horizontal group, the Blackburne and Peel ratio decreased from 0.85 ± 0.16 to 0.67 ± 0.12, and the sagittal tibial slope was increased from 7.7° ± 4.6° to 10.7° ± 3.8° (P < .001). In comparison, the oblique group did not show any significant postoperative changes for these 2 parameters. In the oblique group, 2 patients sustained loss of correction and early failure when the osteotomy remained below the metaphyseal flare on the lateral cortex. Conclusion The oblique osteotomy group showed more normalized postoperative sagittal tibial slope and patellar height. Caution should be exercised not to osteotomize too distally.

Comparison of the effects of amikacin and kanamycins A and B on dimyristoylphosphatidylglycerol bilayers: An infrared spectroscopic investigation☆

Aminoglycoside antibiotics are very effective against severe Gram-negative infections, but their clinical use is associated with nephrotoxic side-effects. The cascade of events leading to acute renal failure involves an impairment of lysosomal phospholipase activity, which is thought to result from the direct interaction of the drugs with the head group of negative phospholipids. Fourier transform infrared spectroscopy was used to study the effects of three aminoglycosides from the kanamycin family (amikacin and kanamycins A and B) on dimyristoylphosphatidylglycerol (DMPG) bilayers at lysosomal pH. The results obtained were consistent with a tightening of the lipidic network caused by the neutralization of the negative head groups of DMPG by the positive charges of the aminoglycosides. These antibiotics induced an increase of the transition temperature of DMPG, a decrease of both the frequency and relative intensity of the hydrogen-bonded carbonyl component, and a decrease of the phosphate antisymmetric band frequency. Kanamycin B, which is known to be the most nephrotoxic drug of the three, exhibited the greatest effects on the transition temperature and on the carbonyl stretching band. A comparison of the nature and extent of the spectral changes led us to conclude that amikacin lies flat on the bilayer surface, whereas kanamycin B is located between the lipidic head groups and quite close to some of the carbonyl groups. Finally, a possible correlation between the importance of bilayers perturbation and the respective inhibitory potency against phospholipases was examined.